Key controlled lock having built-in switch actuator operated by insertion and removal of key



y 1970 E. N. JACOB! 3,520,161

KEY CONTROL LO H NG B T-IN SWITCH ACTUATOR OFERA D BY E ON A REMOVAL OFKEY Tl S1.

Filed July 17, 1968 cots-SW01 IamvmiA/fhmbz y 1970 E. N. JACOB]3,529,161

KEY CONTROLLED LOCK HAVING BUILT-IN SWITCH ACTUATOR OPERATED BYINSERTION AND REMOVAL OF KEY Filed July 17,, 1968 :3 Sheets-$heet UnitedStates Patent 3,520,161 KEY C(PNTROLLED LOCK HAVING BUlLT-IN SWITCHACTUATOR OPERATED BY INSER- TIGN AND REMUVAL OF KEY Edward N. Jacobi,Milwaukee, Wis., assignor to Briggs & Stratton Corporation, Milwaukee,Wis., a corporation of Delaware Filed July 17, 1968, Ser. No. 745,639Int. Cl. E051!) 35/14 US. Cl. 70-387 Claims ABSTRACT OF THE DISCLOSURE Akey controlled tumbler lock with a cylinder rotatable in a bored lockcasing, has a switch actuating lever pivotally mounted in alongitudinally extending slot in the wall of the lock case. The free endof the lever is projected beyond the cylindrical boundary surface of thelock case by the engagement of the straight back edge of the key with afinger on the lever as the key is inserted into the keyway of thecylinder, and is retracted by a spring when the key is withdrawn, atwhich time the finger on the lever enters the keyway.

This invention relates to locks and refers more particularly to ignitionswitch locks for automobiles.

SUMMARY The invention is concerned with the problem of reducingautomobile thefts resulting from the drivers failure to remove theigntion key from the ignition switch lock. It deals with the problem byeffecting closure of a buzzer energizing circuit by the opening of thedoor on the drivers side of the automobile in the event the the ignitionkey is left in the keyway of the lock. Ignition switch locks having thiscapability are presently standard equipment in the cars of at least onelarge automobile manufacturer, but in those cars, the warning buzzercircuit can be disabled by simply withdrawing the key a slightamount-not more than about one-eighth of an inch either before or afterthe door is opened. Needless, to say, this can lead to a habit whichdefeats the entire purpose of the Warning system.

With this invention, the lock controlled switch in the warning buzzercircuit is closed as long the key remains in the lock far enough to keepfrom falling out. Only upon complete removal of the key does the lockcontrolled switch open.

The invention achieves its objective by providing the lock with a switchactuator located in an aperture in the side of the lock case, andyieldingly biased to a retracted position in which a finger on theactuator projects into the keyway of the cylinder when the cylinder isin its locked position of rotation and no key is present therein. Inthis retracted position, no part of the actuator protrudes beyond thecylindrical boundary surface of the lock case. But, upon insertion ofthe key, the finger on the actuator is expelled from the keyway andanother part thereof is projected beyond the side of the lock case. Themovement of the actuator between its retracted and projected positionsis utilized to open and close a switch in the warning buzzer circuit.

The purpose and object of the invention, thus is to "ice provide animproved key controlled lock having a builtin switch actuator which ismovable between a retracted position in which no part thereof protrudesbeyond the side of the lock case and a projected position in which aswitch actuated part thereof does protrude beyond the side of the lockcase; and wherein the actuator occupies its projected position whenevera key is in the lock and until the key is fully removed.

The only prior art known that comes close to disclosing a lock havingthe aforesaid capabilities is the Fitzgerald Pat. No. 2,105,350.

With these observations and objects in mind, the manner in which theinvention achieves its purpose will be appreciated from the followingdescription and the accompanying drawings. This disclosure is intendedmerely to exemplify the invention.

The drawings illustrate one complete example of the physical embodimentsof the invention constructed according to the best mode so far devisedfor the practical application of the principles thereof, and in which:

FIG. 1 is essentially a longitudinal sectional view through a keycontrolled lock embodying this invention, said view illustrating thesituation which obtains when no key is present in the lock;

FIG. 2 is a view similar to FIG. 1, but with a key in the keyway;

FIG. 3 is a cross-sectional view through FIG. 1 on the plane of the line3-3;

FIG. 4 is a cross sectional view through FIG. 2 on the plane of the line44; and

FIG. 5 is an exploded perspective view of the parts of the lockprimarily involved with this invention.

Referring to the drawings, the numeral 6 designates generally a keycontrolled pin tumbler lock of the type commonly used to controlautomobile ignition switches. As is customary, the lock comprises acasing 7 having a bore 8 in which a lock cylinder 9 is rotatablyreceived. The cylinder is secured against rotation by a group of pintumblers and drivers, collectively designated by the numeral 10, untilinsertion of a proper key 11 into the keyway 12 of the lock cylinder.Insertion of the key frees the cylinder for rotation and enables switchactuating motion to be imparted to the contactor of the ignition switch(not shown) through a driver 13 which projects from the rear or innerend of the cylinder.

Since the purpose of the invention is to control an electric circuitasfor instancethe energizing circuit of a warning buzzer by the presenceor absence of the key in the lock, the lock case 7 has a switch actuator14 mounted therein for movement between a retracted position shown inFIG. 1 and a projected position shown in FIG. 1 and a projected positionshown in FIG. 2. Movement of the actuator 14 from one to the other ofthese positions, is utilized to actuate a micro-switch 15 mounted injuxaposition to the lock. In a customary installation, the switch 15 andadoor controlled switch in series circuit therewith (not shown) controlsenergization of a warning buzzer, the sounding of which indicates thatthe key has not been removed from the lock.

The actuator 14 is a fiat sided lever-preferably stamped from sheetmetal. It is received in a longitudinally extending slot 17 which isopen throughout its length to the cylindrical boundary surface of thelock case and communicates with the bore 8 through a hole 18. Theactuator lever is pivotally assembled with the lock case by theinsertion of an embossure 19 protruding from one side of the lever intoa recess or cavity 20 in the adjacent side of the slot 17 The recess orcavity 20 opens to the front end of the lock case, and the embossure isretained in the recess 20 by the attachment of an escutcheon cap 21 tothe front end of the lock.

Preferably, a hardened steel apertured disc 22 is interposed between thefront end of the lock case and the escutcheon cap to provide protectionagainst drilling into the lock. The inner surface of this hardened steeldisc closes the open mouth of the recess 20 and thus confines theactuator lever 14 in position.

A finger 23 on the actuator lever projects through the hole 18 and intothe keyway 12 of the lock cylinder when the cylinder is in its lockedposition of rotation, and no key is present in the keyway. Thisrelationship of the parts (illustrated in FIGS. 1 and 3) is yieldinglymaintained by a spring 24 confined between the finger 23 and theopposite wall 25 of a recess 26 formed in the lock case and opening tosaid slot 17 and also the hole 18.

The spring produced rocking movement of the actuator lever 14 is limitedby the engagement of its free end with a surface 27 which constitutesthe bottom of the adjacent portion of the slot 17. In this springretracted position of the actuating lever, no part thereof projects outof the mouth of the slot 17 or protrudes beyond the cylindrical surfaceboundary of the lock case.

Upon insertion of the key, however, the finger 23 is expelled from thekeyway and, as a result, the actuator lever 14 is rocked about its pivot19 to project the outer free end of the lever beyond the cylindricalboundary surface of the lock case and, in so doing, depress the driveror contact controlling member of the microswitch 15, as shown in FIG. 2.

Since the keyway 12 opens to the cylindrical boundary surface of thecylinder, at least along that portion of the length of the keyway whichencompasses the group of pin tumblers and drivers, and since the backedge 30 of the key is flush with the cylindrical boundary of the lockcylinder, it follows that the actuator undergoes no change in positionfrom that shown in FIG. 2 when the cylinder is turned by means of thekey. Also, since the finger 23 is located close to the pivot 19 for theactuator lever, and opposite the front end of the group of pin tumblersand drivers, it follows that the actuator lever 14 will occupy itsprojected position as long as the key remains far enough in the keywayto prevent its falling out. This will be evident from the dotted lineillustration DL of the nose of the key in FIG. 2.

It will be noted that the outer edge of the actuator lever 14 is soshaped that, even in its projected position, substantially only its freeend portion 31 protrudes beyond the cylindrical boundary surface of thelock case. This relationship enables the lock to be mounted in theconventional way, which requires that a substantial part of the lengthof the lock case be received in a relatively close fitting round hole inthe supporting structure in which the lock is mounted.

From the foregoing description taken in connection with the accompanyingdrawings, it will be apparent to those skilled in this art that thisinvention provides a significantly improved ignition lock forautomobiles in which the presence of absence of the key is utilized tocontrol the energizing circuit of a warning buzzer.

Those skilled in the art will also appreciate that the invention can beembodied in forms other than as herein disclosed for purposes ofillustration.

The invention is defined by the following claims.

I claim:

1. In a key controlled lock wherein a cylinder having a keyway isrotatably mounted in a bore of a lock case and secured against rotationfrom a locked position by key controlled tumblers until insertion of aproper key into the keyway of the cylinder, the keyway having an openedge debouching to the cylindrical boundary surface of the cylinder froma point closely adjacent to the mouth of the keyway, said open edgebeing closed by the back edge of a proper key in the keyway and saidback edge of the key when so posi tioned being fiush with and formingsubstantially a continuation of the cylindrical boundary surface of thecylinder, insertion and removal of the key requiring the cylinder to bein a predetermined position of rotation, said lock being characterizedby:

(A) the lock case having a longitudinally extending slot opening to itsexterior boundary surface and communicating with the bore through a holenear the mouth of the bore and hence near the mouth of the keyway,

said hole being so located that the open edge of the keyway alignstherewith when the cylinder is in said predetermined position ofrotation;

(B) a switch actuating lever in said slot,

said lever having a front end in that portion of the slot that isadjacent to the mouth of the keyway and having a rear end remotetherefrom;

(C) pivot means pivotally connecting the front end portion of the switchactuating lever with the lock case and mounting the lever for movementbetween a defined retracted position in which no part thereof protrudesfrom the slot, and a projected position in which the rear end portion ofthe lever protrudes from the slot and projects beyond the exteriorboundary surface of the lock case;

(D) a finger on the switch actuating lever adjacent to but rearwardly ofits pivoted front end, said finger being received in said hole andprojecting therethrough into the keyway when the switch actuating leveris in its retracted position, to be expelled from the keyway by a properkey inserted into the keyway, whereby the switch actuating lever is heldin its projected position by the key,

the location of the hole and said finger adjacent to the mouth of thekeyway assuring that the switch actuating lever will be held in itsprojected position until the key is withdrawn far enough to preclude itsremaining in the keyway when released; and

(E) a spring reacting between the switch actuating lever and the lockcase, yieldingly urging the lever to its defined retracted position.

2. The lock of claim 1, wherein the switch actuating lever issubstantially a bellcrank having a long arm and a short arm, and

wherein the pivot means is located near the junction of Said arms, thelong arm extending lengthwise of the slot and lying wholly within theslot when the switch actuating lever is in its retracted position, buthaving its free end portion protruding therefrom in the projectedposition of the lever, and the short arm providing said finger whichprojects through said hole and into the keyway in the retracted positionof the lever.

3. The lock of claim 2, wherein the spring is seated in a pocket in thelock case in juxtaposition to the junction of the slot and the hole,

said pocket having a surface facing the short arm of the lever, and thespring being confined between said surface and the short arm.

4. The lock of claim 2, wherein the pivot means comprises an embossureon the lever seated in a recess in the adjacent side of the slot andopening to the front end of the lock case; and

further characterized by an escutcheon cap secured to the front end ofthe lock case and closing the open front end of the recess.

5. The lock of claim 2, wherein the long arm of the 5 lever is shaped toprovide an outwardly projecting finger on its free end to minimize theportion of the lever that protrudes from the slot in the projectedposition of the actuator.

References Cited UNITED STATES PATENTS 2,063,088 12/1936 Fitzgerald70-252 2,105,350 1/1938 Fitzgerald 70-264 2,261,868 11/1941 Arriaza2006l.66 2,613,258 10/1952 McKeon 34052 Jacobsen 34052 Kiwi 200153 Rinket a1. 70-237 5 RICHARD E. MOORE, Primary Examiner R. L. WOLFE,Assistant Examiner US. Cl. X.R.

Azano 34052 10 70 372, 441; 200-61.66; 340--64

